Scully Kathleen M, Rosenfeld Michael G
Howard Hughes Medical Institute, School of Medicine, University of California, San Diego, 9500 Gilman Drive, Room 345, La Jolla, CA 92093, USA.
Science. 2002 Mar 22;295(5563):2231-5. doi: 10.1126/science.1062736.
During mammalian pituitary gland development, distinct cell types emerge from a common primordium. Appearance of specific cell types occurs in response to opposing signaling gradients that emanate from distinct organizing centers. These signals induce expression of interacting transcriptional regulators, including DNA binding-dependent activators and DNA binding-independent transrepressors, in temporally and spatially overlapping patterns. Together they synergistically regulate precursor proliferation and induction of distinct cell types. Terminal cell type differentiation requires selective gene activation strategies and long-term active repression, mediated by cell type-specific and promoter-specific recruitment of coregulatory complexes. These mechanisms imply the potential for flexibility in the ultimate identity of differentiated cell types.
在哺乳动物垂体发育过程中，不同的细胞类型从共同的原基中产生。特定细胞类型的出现是对来自不同组织中心的相反信号梯度的响应。这些信号以时间和空间上重叠的模式诱导相互作用的转录调节因子的表达，包括依赖DNA结合的激活因子和不依赖DNA结合的反式抑制因子。它们共同协同调节前体细胞的增殖和不同细胞类型的诱导。终末细胞类型的分化需要选择性基因激活策略和长期的主动抑制，这是由共调节复合物的细胞类型特异性和启动子特异性募集介导的。这些机制意味着分化细胞类型的最终身份具有灵活性的潜力。
